This document describes the current stable version of Celery (4.0). For development docs, go here.

Source code for celery.backends.filesystem

# -*- coding: utf-8 -*-
"""File-system result store backend."""
from __future__ import absolute_import, unicode_literals
import os
import locale
from kombu.utils.encoding import ensure_bytes
from celery import uuid
from celery.exceptions import ImproperlyConfigured
from celery.backends.base import KeyValueStoreBackend

# Python 2 does not have FileNotFoundError and IsADirectoryError
try:
    FileNotFoundError
except NameError:
    FileNotFoundError = IOError
    IsADirectoryError = IOError

default_encoding = locale.getpreferredencoding(False)

E_PATH_INVALID = """\
The configured path for the file-system backend does not
work correctly, please make sure that it exists and has
the correct permissions.\
"""


[docs]class FilesystemBackend(KeyValueStoreBackend): """File-system result backend. Arguments: url (str): URL to the directory we should use open (Callable): open function to use when opening files unlink (Callable): unlink function to use when deleting files sep (str): directory separator (to join the directory with the key) encoding (str): encoding used on the file-system """ def __init__(self, url=None, open=open, unlink=os.unlink, sep=os.sep, encoding=default_encoding, *args, **kwargs): super(FilesystemBackend, self).__init__(*args, **kwargs) self.url = url path = self._find_path(url) # We need the path and separator as bytes objects self.path = path.encode(encoding) self.sep = sep.encode(encoding) self.open = open self.unlink = unlink # Lets verify that we've everything setup right self._do_directory_test(b'.fs-backend-' + uuid().encode(encoding)) def _find_path(self, url): if not url: raise ImproperlyConfigured( 'You need to configure a path for the File-system backend') if url is not None and url.startswith('file:///'): return url[7:] def _do_directory_test(self, key): try: self.set(key, b'test value') assert self.get(key) == b'test value' self.delete(key) except IOError: raise ImproperlyConfigured(E_PATH_INVALID) def _filename(self, key): return self.sep.join((self.path, key))
[docs] def get(self, key): try: with self.open(self._filename(key), 'rb') as infile: return infile.read() except FileNotFoundError: pass
[docs] def set(self, key, value): with self.open(self._filename(key), 'wb') as outfile: outfile.write(ensure_bytes(value))
[docs] def mget(self, keys): for key in keys: yield self.get(key)
[docs] def delete(self, key): self.unlink(self._filename(key))